1. Field of the Invention
The present invention relates to an ultrasound scanning assistance apparatus for diagnosis of a breast cancer and an ultrasound scanning method, and more particularly, to an ultrasound scanning assistance apparatus that hermetically contacts a skin of a human body part using a dedicated soft membrane and ultrasonically images the human body part being contacted.
The present invention is derived from a research conducted as part of the new technology convergence type growth engine program with the support of the Korea science and engineering foundation funded by the ministry of education and science technology. [Grant number: 2012K001520, Title: Development in a lesion detection technology for a breast ultrasound.]
2. Description of the Related Art
Globally, a breast cancer takes the first ranking of incidence of female cancers. In Korea, most of breast cancer patients are young at the age of forties. Mammography is generally used in diagnosis of the breast cancer. However, in regard to oriental women with over 40% of dense breast tissue, efficiency of the mammography is relatively low, that is, no more than 0.6% of a positive predictive value. Therefore, two-dimensional (2D) breast ultrasound imaging has been additionally performed. In this case, a breast cancer detection rate reaches about 95% or more. A three-dimensional (3D) breast ultrasound, which is being recently developed, easily identifies a location, size, and shape of a tumor, increases diagnosis accuracy of the breast cancer, and facilitates biopsies for a definitive diagnosis and treatment.
When performing the 3D breast ultrasound imaging, a meaningful image may be obtained only when a transducer device scans a skin in close contact with the skin so that the ultrasound effectively propagates through a human body. For this, gel-type assistant fluid needs to be disposed between the transducer device and the skin without air intervened.
A generally used method for the 3D ultrasound imaging outputs an ultrasonic signal from a transducer device such as a one-dimensional (1D) array lead zirconate titanate (PZT), and analyzes and post-processes a time interval between reflected signals, thereby reproducing a 2D image. In addition, the method constructs information with respect to a 3D space by continuously obtaining a 2D image slice by moving a transducer array in a direction orthogonal to the 1D array. According to a recently researched method, a 3D image may be simultaneously reproduced directly from a transducer device having a 2D array.
The 1D transducer method needs scanning of a transducer and therefore has a limit in synchronism. That is, a difference in obtaining time of an image between start and end of scanning need to be taken into consideration in reading. When a plurality of 3D images are obtained by a plurality of transducers and integrated into an entire 3D image, a mismatch between images obtained by the plurality of transducers may be generated. Furthermore, since the images are obtained on a time basis, a movement of a human body during the image obtainment needs to be considered. (Refer to US 2010/0179429 A1 FIGS. 1 and 6b, and US 2012/0089026 A1 FIG. 4a)
Recently, elastography showing an exclusive performance in tumor diagnosis is being spotlighted as a functional ultrasound imaging method. Elastography reconstructs an elastic property image using a difference between ultrasound images obtained by oscillating a particular surface of a human body at a short time interval of about tens of hertz (Hz) from an outside, and visualizes a change in human parenchymal properties, in particular, elastic properties. In case of diagnosis of a breast cancer, the elastography is particularly useful in determining malignancy and benignancy of a tumor since the elastic properties are obviously different between a malignant tumor, which is several times harder than a surrounding parenchyma, and the surrounding parenchyma in an image obtained by the elastography.
However, since the elastography extracts the elastic properties by applying oscillation to the human body at a short time interval, a method of applying oscillation directly influences an image quality. In addition, a structural problem may be caused since an ultrasound needs to be generated and collected by a transducer simultaneously with when a change in the elastic properties of the human body occurs. That is, in a conventional system, an oscillation apparatus of tens of Hz is operated integrally with a portable transducer and, at this time, an ultrasound image is simultaneously obtained using the transducer. In this case, a difference image is obtained by oscillating only a portion contacting the transducer. However, since oscillation is also generated from the portable transducer, it is difficult to maintain constant oscillation. (Refer to 2012/0136250 A1 FIG. 2)